Event location determination

Abstract

A method of determining a location of an event of interest by processing signals from a satellite positioning system. The method comprises receiving recorded blocks of data samples of a satellite broadcast including blocks recorded at the approximate location of the event of interest, each block including one or more timestamps generated within a first portable device at which the samples were recorded; receiving a time of occurrence of the event recorded independently of the samples; comparing the timestamps and the time of occurrence to identify at least one block corresponding to the event; and processing the data samples of the identified at least one block to derive position information approximating the location of the event.

1. A method of determining a location of an event of interest by processing signals from a satellite positioning system, the method comprising:
 receiving recorded blocks of data samples of a satellite broadcast including blocks recorded at the approximate location of the event of interest, each block including one or more timestamps generated within a first portable device at which the samples were recorded; 
 receiving a time of occurrence of the event recorded independently of the samples; 
 comparing the timestamps and the time of occurrence to identify at least one block corresponding to the event; and 
 processing the data samples of the identified at least one block to derive position information approximating the location of the event. 
 
     
     
       2. The method of  claim 1 , wherein the time of occurrence of the event is recorded at a second portable device. 
     
     
       3. The method of  claim 1  or  2 , wherein the at least one identified block comprises a plurality of blocks and the step of processing the data samples comprises:
 deriving at least one position corresponding to each block; and 
 interpolating among the derived positions to approximate the location of the event, based upon the recorded time of occurrence. 
 
     
     
       4. The method of  claim 1  or  2 , wherein the step of processing the data samples comprises:
 deriving at least one position and at least one velocity corresponding to the at least one identified block; and 
 using the derived position and velocity to approximate the location of the event, based on the recorded time of occurrence. 
 
     
     
       5. The method of  claim 1  or  2 , further comprising compensating for an error between the recorded time of occurrence and the timestamps. 
     
     
       6. The method of  claim 2 , wherein the event of interest is the capture of an image or a sequence of images and the second portable device is a camera. 
     
     
       7. The method of  claim 1  or  2 , wherein the samples comprise intermediate frequency downconverted data samples. 
     
     
       8. A method of determining a location of an event of interest by processing signals from a satellite positioning system, the method comprising:
 recording blocks of data samples of a satellite broadcast, including blocks recorded at the approximate location of the event of interest, each block including one or more timestamps; 
 recording a time of occurrence of the event; and 
 determining the location of capture according to the method of  claim 1 . 
 
     
     
       9. A computer program comprising computer program code means adapted to perform all the steps of  claim 1  or  2  when said program is run on a computer. 
     
     
       10. A computer program as claimed in  claim 9  embodied on a computer-readable medium. 
     
     
       11. Apparatus for determining a location of an event of interest by processing signals from a satellite positioning system, the apparatus comprising:
 first receiving means, adapted to receive recorded blocks of data samples of a satellite broadcast including blocks recorded at the approximate location of the event of interest, each block including one or more timestamps generated within a first portable device at which the samples were recorded; 
 second receiving means, adapted to receive a time of occurrence of the event recorded independently of the samples; and 
 a processor, adapted to compare the timestamps and the time of occurrence to identify at least one block corresponding to the event and to process the data samples of the identified at least one block to derive position information approximating the location of the event. 
 
     
     
       12. Apparatus for determining a location of an event of interest by processing signals from a satellite positioning system, the apparatus comprising:
 a first portable device adapted to record blocks of data samples of a satellite broadcast, including blocks recorded at the approximate location of the event of interest, each block including one or more timestamps generated within the device; and 
 apparatus according to  claim 11 . 
 
     
     
       13. The apparatus of  claim 12 , further comprising a second portable device for recording the time of occurrence of the event. 
     
     
       14. The apparatus of  claim 13 , wherein the event of interest is the capture of an image or a sequence of images and the second portable device is a camera.